Local activation of CB1 receptors by synthetic and endogenous cannabinoids dampens burst firing mode of reticular thalamic nucleus neurons in rats under ketamine anesthesia.

The reticular thalamic nucleus (RTN) is a thin shell that covers the dorsal thalamus and controls the overall information flow from the thalamus to the cerebral cortex through GABAergic projections that contact thalamo-cortical neurons (TC). RTN neurons receive glutamatergic afferents fibers from neurons of the sixth layer of the cerebral cortex and from TC collaterals. The firing mode of RTN neurons facilitates the generation of sleep-wake cycles; a tonic mode or desynchronized mode occurs during wake and REM sleep and a burst-firing mode or synchronized mode is associated with deep sleep. Despite the presence of cannabinoid receptors CB1 (CB1Rs) and mRNA that encodes these receptors in RTN neurons, there are few works that have analyzed the participation of endocannabinoid-mediated transmission on the electrical activity of RTN. Here, we locally blocked or activated CB1Rs in ketamine anesthetized rats to analyze the spontaneous extracellular spiking activity of RTN neurons. Our results show the presence of a tonic endocannabinoid input, since local infusion of AM 251, an antagonist/inverse agonist, modifies RTN neurons electrical activity; furthermore, local activation of CB1Rs by anandamide or WIN 55212-2 produces heterogeneous effects in the basal spontaneous spiking activity, where the main effect is an increase in the spiking rate accompanied by a decrease in bursting activity in a dose-dependent manner; this effect is inhibited by AM 251. In addition, previous activation of GABA-A receptors suppresses the effects of CB1Rs on reticular neurons. Our results show that local activation of CB1Rs primarily diminishes the burst firing mode of RTn neurons.

Interspecific interactions disrupted by roads.

Roads have pervasive impacts on wildlife, including habitat loss and fragmentation, road mortality, habitat pollution and increased human use of habitats surrounding them. However, the effects of roads on interspecific interactions are less understood. Here we provide a synthesis of the existing literature on how species interactions may be disrupted by roads, identify knowledge gaps, and suggest avenues for future research and conservation management. We conducted a systematic search using the Web of Science database for each species interaction (predation, competition, mutualism, parasitism, commensalism and amensalism). These searches yielded 2144 articles, of which 195 were relevant to our topic. Most of these studies focused on predation (50%) or competition (24%), and less frequently on mutualism (17%) or, parasitism (9%). We found no studies on commensalism or amensalism. Studies were biased towards mammals from high-income countries, with most conducted in the USA (34%) or Canada (18%). Our literature review identified several patterns. First, roads disrupt predator-prey relationships, usually with negative impacts on prey populations. Second, new disturbed habitats created in road corridors often benefit more competitive species, such as invasive species, although some native or endangered species can also thrive there. Third, roads degrade mutualistic interactions like seed dispersal and pollination. Fourth, roads can increase parasitism rates, although the intensity of the alteration is species specific. To reduce the negative impacts of roads on interspecific interactions, we suggest the following management actions: (i) verges should be as wide and heterogenous as possible, as this increases microhabitat diversity, thus enhancing ecosystem services like pollination and seed dispersal; (ii) combining different mowing regimes can increase the complexity of the habitat corridor, enabling it to act as a habitat for more species; (iii) the use of de-icing salts should be gradually reduced and replaced with less harmful products or maintenance practices; (iv) wildlife passes should be implemented in groups to reduce animal concentrations inside them; (v) periodic removal of carcasses from the road to reduce the use of this resource by wildlife; and (vi) implementation of traffic-calming schemes could enhance interspecific interactions like pollination and avoid disruption of predator-prey relationships.

Nearby night lighting, rather than sky glow, is associated with habitat selection by a top predator in human-dominated landscapes.

Artificial light at night (ALAN) is increasing in extent and intensity across the globe. It has been shown to interfere with animal sensory systems, orientation and distribution, with the potential to cause significant ecological impacts. We analysed the locations of 102 mountain lions (Puma concolor) in a light-polluted region in California. We modelled their distribution relative to environmental and human-disturbance variables, including upward radiance (nearby lights), zenith brightness (sky glow) and natural illumination from moonlight. We found that mountain lion probability of presence was highly related to upward radiance, that is, related to lights within approximately 500 m. Despite a general pattern of avoidance of locations with high upward radiance, there were large differences in degree of avoidance among individuals. The amount of light from artificial sky glow was not influential when included together with upward radiance in the models, and illumination from moonlight was not influential at all. Our results suggest that changes in visibility associated with lunar cycles and sky glow are less important for mountain lions in their selection of light landscapes than avoiding potential interactions with humans represented by the presence of nearby lights on the ground. This article is part of the theme issue 'Light pollution in complex ecological systems'.

Lack of SARS-CoV-2 RNA evidence in the lungs from wild European polecats (Mustela putorius) from Spain.

Data on SARS-CoV-2 infection in wildlife species is limited. The high prevalences found in mustelid species such as free-ranging American minks (Neovison vison) and domestic ferrets (Mustela putorius furo) justify the study of this virus in the closely related autochthonous free-ranging European polecat (Mustela putorius). We analysed lung samples from 48 roadkilled polecats collected when the human infection reached its highest levels in Spain (2020-2021). We did not detect infections by SARS-CoV-2; however, surveillance in wild carnivores and particularly in mustelids is still warranted, due to their susceptibility to this virus.

Boron-containing compounds on neurons: Actions and potential applications for treating neurodegenerative diseases.

Boron-containing compounds (BCC) exert effects on neurons. After the expanding of both the identification and synthesis of new BCC, novel effects in living systems have been reported, many of these involving neuronal action. In this review, the actions of BCC on neurons are described; the effects have been inferred by boron deprivation or addition. Also, the effects can be related to those mediated by interaction on ionic channels, G-protein coupled receptors, or other receptors exerting modification on neuronal behavior. Additionally, BCC have exhibited effects by the modulation of inflammation or oxidative processes. BCC are expanding as drugs. Deprivation of boron sources from the diet shows the role of some natural BCC. However, the observations of several new synthesized compounds suggest their ability to act with attractive potency, efficacy, and long-term action on neuronal receptors or processes related with the origin and evolution of neurodegenerative processes. The details of BCC-target interactions are currently being elucidated in progress, as those observed from BCC-protein crystal complexes. Taking all of the above into account, the expansion is presumably near to having studies on the application of BCC as drugs on specific targets for treating neurodegenerative diseases.

Tonic serotonergic input increases the burst firing mode and diminishes the firing rate of reticular thalamic nucleus neurons through 5-HT1A receptors activation in anesthetized rats.

The reticular thalamic nucleus (RTn) is a thin shell of GABAergic neurons that covers the dorsal thalamus that regulate the global activity of all thalamic nuclei. RTn controls the flow of information between thalamus and cerebral cortex since it receives glutamatergic information from collaterals of thalamo-cortical (TCs) and cortico-thalamic neurons. It also receives aminergic information from several brain stem nuclei, including serotonergic fibers originated in the dorsal raphe nucleus. RTn neurons express serotonergic receptors including the 5-HT1A subtype, however, the role of this receptor in the RTn electrical activity has been scarcely analyzed. In this work, we recorded in vivo the unitary spontaneous electrical activity of RTn neurons in anesthetized rats; our study aimed to obtain information about the effects of 5-HT1A receptors in RTn neurons. Local application of fluoxetine (a serotonin reuptake inhibitor) increases burst firing index accompanied by a decrease in the basal spiking rate. Local application of different doses of serotonin and 8-OH-DPAT (a specific 5-HT1A receptor agonist) causes a similar response to fluoxetine effects. Local 5-HT1A receptors blockade produces opposite effects and suppresses the effect by 8-OH-DPAT. Our findings indicate the presence of a serotonergic tonic discharge in the RTn that increases the burst firing index and simultaneously decreases the basal spiking frequency through 5-HT1A receptors activation.

Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences.

Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental datasets, that these types of designs usually give less biased estimates than simpler observational designs. We propose a model-based approach to combine study estimates that may suffer from different levels of study design bias, discuss the implications for evidence synthesis, and how to facilitate the use of more credible study designs.

Host dispersal shapes the population structure of a tick-borne bacterial pathogen.

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.

Bird on the wire: Landscape planning considering costs and benefits for bird populations coexisting with power lines.

Power-line grids are increasingly expanding worldwide, as well as their negative impacts on avifauna, namely the direct mortality through collision and electrocution, the reduction of breeding performance, and the barrier effect. On the other hand, some bird species can apparently benefit from the presence of power lines, for example perching for hunting purposes or nesting on electricity towers. In this perspective essay, we reviewed the scientific literature on both costs and benefits for avifauna coexisting with power lines. Overall, we detected a generalized lack of studies focusing on these costs or benefits at a population level. We suggest that a switch in research approach to a larger spatio-temporal scale would greatly improve our knowledge about the actual effects of power lines on bird populations. This research approach would facilitate suitable landscape planning encompassing both mitigation of costs and promotion of benefits for bird populations coexisting with power lines. For example, the strategic route planning of electricity infrastructures would limit collision risk or barrier effects for threatened bird populations. Concurrently, this strategic route planning would promote the range expansion of threatened populations of other bird species, by providing nesting structures in treeless but potentially suitable landscapes. We suggest establishing a collaborative dialogue among the scientific community, governments, and electricity companies, with the aim to produce a win-win scenario in which both biodiversity conservation and infrastructure development are integrated in a common strategy.

Striatum and globus pallidus control the electrical activity of reticular thalamic nuclei.

Through GABAergic fibers, globus pallidus (GP) coordinates basal ganglia global function. Electrical activity of GP neurons depends on their membrane properties and afferent fibers, including GABAergic fibers from striatum. In pathological conditions, abnormal electrical activity of GP neurons is associated with motor deficits. There is a GABAergic pathway from the GP to the reticular thalamic nucleus (RTn) whose contribution to RTn neurons electrical activity has received little attention. This fact called our attention because the RTn controls the overall information flow of thalamic nuclei to cerebral cortex. Here, we study the spontaneous electrical activity of RTn neurons recorded in vivo in anesthetized rats and under pharmacological activation or inhibition of the GP. We found that activation of GP predominantly diminishes the spontaneous RTn neurons firing rate and its inhibition increases their firing rate; however, both activation and inhibition of GP did not modified the burst index (BI) or the coefficient of variation (CV) of RTn neurons. Moreover, stimulation of striatum predominantly diminishes the spiking rate of GP cells and increases the spiking rate in RTn neurons without modifying the BI or CV in reticular neurons. Our data suggest a GP tight control over RTn spiking activity.

Dopamine-dependent modulation of rat globus pallidus excitation by nicotine acetylcholine receptors.

The globus pallidus (GP) coordinates information processing in the basal ganglia nuclei. The contribution of nicotinic cholinergic receptors (nAChRs) to the spiking activity of GP neurons is largely unknown. Several studies have reported that the effect of nAChRs in other nuclei depends on dopaminergic input. Via in vivo single unit extracellular recordings and intranuclear drug infusions, we analyzed the effects of local activation and blockade of nAChRs in neurons of both sham and 6-hydroxydopamine (6-OHDA)-lesioned rats. In sham rats, the local application of nicotine and edrophonium (an acetylcholinesterase inhibitor) increases GP neurons spiking rate. Local application of mecamylamine, a neuronal nicotinic cholinergic antagonist, diminishes pallidal neurons spiking rate, an effect not produced by d-tubocurarine, a peripheral nicotinic cholinergic antagonist. Moreover, mecamylamine blocks the excitatory effect evoked by nicotine and edrophonium. In 6-OHDA-lesioned rats, local infusion of nicotine does not change pallidal neurons firing rate. Our results show that there is a tonic cholinergic input to the GP that increases their spiking rate through the activation of nAChRs and that this effect depends on functional dopaminergic pathways.

Clinical and Pharmaceutical Solutions through Analysis (CPSA BRASIL 2015): on the way to innovation - pharmaceutical/analytical technology, regulation and knowledge management.

Clinical and Pharmaceutical Solutions through Analysis, São Paulo, Brazil, 3-5 August 2015 The 2nd Annual Symposium on Clinical and Pharmaceutical Solutions through Analysis was held on 3-5 August 2015 at Club Transatlântico, São Paulo, Brazil. This annual meeting began in 2014 and was the first industry-led event in Brazil to focus on the specific needs of industry researchers while bringing together technology and regulators. The goal of CPSA is to provide an in-depth review of innovative technology and industry practices through open discussion of industry-related issues and needs. Education and specialized training are the foundation of all CPSA events. As the industry has evolved so has CPSA. The CPSA annual meeting thrived with high quality scientific content, open interaction from industry opinion leaders and a collegial environment.

The local application of a flavonoid, (-)-epicatechin, increases the spiking of globus pallidus neurons in a dose-dependent manner and diminishes the catalepsy induced by haloperidol.

Flavonoids are natural substances obtained from plants. Most flavonoids cross the blood-brain barrier and exert a wide range of effects on the central nervous system. These actions have been attributed to the modulation of GABA-A receptors. Although motor systems in the central nervous system express a high density of GABA-A receptors, physiological studies about the effects of flavonoids on motor nuclei are scarce. Among the nuclei of the basal ganglia, the globus pallidus is potentially important for the processing of information related to movement. The electrical activity of globus pallidus neurons depends on the GABAergic fibers coming from the striatum and recurrent collateral fibers. It is known that the basal activity of the globus pallidus is modified by blocking dopaminergic receptors. In the present work, we analyzed the effects of the local application of a flavonoid, (-)-epicatechin, on the spiking of globus pallidus neurons in chloral hydrate-anesthetized rats and determined whether (-)-epicatechin applied bilaterally to the globus pallidus can modify the catalepsy induced by systemic administration of haloperidol. The results showed that (-)-epicatechin increased the basal firing of globus pallidus neurons in a dose-dependent manner and antagonized the inhibitory effect of GABA. Bilateral infusion of (-)-epicatechin to the globus pallidus diminished the catalepsy induced by haloperidol.

rAvis: an R-package for downloading information stored in Proyecto AVIS, a citizen science bird project.

Citizen science projects store an enormous amount of information about species distribution, diversity and characteristics. Researchers are now beginning to make use of this rich collection of data. However, access to these databases is not always straightforward. Apart from the largest and international projects, citizen science repositories often lack specific Application Programming Interfaces (APIs) to connect them to the scientific environments. Thus, it is necessary to develop simple routines to allow researchers to take advantage of the information collected by smaller citizen science projects, for instance, programming specific packages to connect them to popular scientific environments (like R). Here, we present rAvis, an R-package to connect R-users with Proyecto AVIS (http://proyectoavis.com), a Spanish citizen science project with more than 82,000 bird observation records. We develop several functions to explore the database, to plot the geographic distribution of the species occurrences, and to generate personal queries to the database about species occurrences (number of individuals, distribution, etc.) and birdwatcher observations (number of species recorded by each collaborator, UTMs visited, etc.). This new R-package will allow scientists to access this database and to exploit the information generated by Spanish birdwatchers over the last 40 years.

Refugia, colonization and diversification of an arid-adapted bird: coincident patterns between genetic data and ecological niche modelling.

Phylogeographical studies are common in boreal and temperate species from the Palaearctic, but scarce in arid-adapted species. We used nuclear and mitochondrial markers to investigate phylogeography and to estimate chronology of colonization events of the trumpeter finch Bucanetes githagineus, an arid-adapted bird. We used 271 samples from 16 populations, most of which were fresh samples but including some museum specimens. Microsatellite data showed no clear grouping according to the sampling locations. Microsatellite and mitochondrial data showed the clearest differentiation between Maghreb and Canary Islands and between Maghreb and Western Sahara. Mitochondrial data suggest differentiation between different Maghreb populations and among Maghreb and Near East populations, between Iberian Peninsula and Canary Islands, as well as between Western Sahara and Maghreb. Our coalescence analyses indicate that the trumpeter finch colonized North Africa during the humid Marine Isotope Stage 5 (MIS5) period of the Sahara region 125 000 years ago. We constructed an ecological niche model (ENM) to estimate the geographical distribution of climatically suitable habitats for the trumpeter finch. We tested whether changes in the species range in relation to glacial-interglacial cycles could be responsible for observed patterns of genetic diversity and structure. Modelling results matched with those from genetic data as the species' potential range increases in interglacial scenarios (in the present climatic scenario and during MIS5) and decreases in glacial climates (during the last glacial maximum, LGM, 21 000 years ago). Our results suggest that the trumpeter finch responded to Pleistocene climatic changes by expanding and contracting its range.

Striatal input- and rate-dependent effects of muscarinic receptors on pallidal firing.

The globus pallidus (GP) plays a key role in the overall basal ganglia (BG) activity. Despite evidence of cholinergic inputs to GP, their role in the spiking activity of GP neurons has not received attention. We examine the effect of local activation and blockade of muscarinic receptors (MRs) in the spontaneous firing of GP neurons both in normal and ipsilateral striatum-lesioned rats. We found that activation of MRs produces heterogeneous responses in both normal and ipsilateral striatum-lesioned rats: in normal rats the response evoked by MRs depends on the predrug basal firing rate; the inhibition evoked by MRs is higher in normal rats than in striatum-lesioned rats; the number of neurons that undergo inhibition is lower in striatum-lesioned rats than in normal rats. Our data suggest that modulation of MRs in the GP depends on the firing rate before their activation and on the integrity of the striato-pallidal pathway.

Wire marking results in a small but significant reduction in avian mortality at power lines: a BACI designed study.

BACKGROUND: Collision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published. METHODOLOGY/PRINCIPAL FINDINGS: We provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV-45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking. CONCLUSIONS: Our results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.

Meta-analysis of the effectiveness of marked wire in reducing avian collisions with power lines.

Collisions of birds with power transmission and distribution lines have been documented for many species, and cause millions of casualties worldwide. Attempts to reduce mortality from such collisions include placing bird flight diverters (i.e., wire markers in the form of, e.g., spirals, swivels, plates, or spheres) on static and some electrified wires to increase their visibility. Although studies of the effectiveness of such devices have yielded contradictory results, the implementation of flight diverters is increasing rapidly. We reviewed the results of studies in which transmission or distribution wires were marked and conducted a meta-analysis to examine the effectiveness of flight diverters in reducing bird mortality. We included in our meta-analysis all studies in which researchers searched for carcasses of birds killed by a collision with wires. In those studies that also included data on flight frequency, we examined 8 covariates of effectiveness: source of data, study design, alternate design (if marked and unmarked spans were alternated in the same line), periodicity of searches for carcasses, width of the search transect, and number of species, lines, and stretches of wire searched. The presence of flight diverters was associated with a decrease in bird collisions. At unmarked lines, there were 0.21 deaths/1000 birds (n =339,830) that flew among lines or over lines. At marked lines, the mortality rate was 78% lower (n =1,060,746). Only the number of species studied had a significant influence on effect size; this was larger in studies that addressed more species. When comparing mortality at marked and unmarked lines, we recommend use of the same time intervals and habitats and standardizing the periodicity of carcass searches.